<!doctype HTML>
<html>
<meta charset="utf8">
<title>Content Visibility: ContentVisibilityAutoStateChange event.</title>
<link rel="author" title="Vladimir Levin" href="mailto:vmpstr@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-contain/#content-visibility">
<meta name="assert" content="ContentVisibilityAutoStateChange does not fire on disconnected element">

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/common/rendering-utils.js"></script>

<style>
.spacer {
  height: 10000px;
}
#bottomdiv {
  content-visibility: auto;
}
</style>

<div class=spacer></div>
<div id=bottomdiv></div>

<script>
promise_test(t => new Promise(async (resolve, reject) => {
  // Make sure the first "contentvisibilityautostatechange" event has fired before the test.
  await new Promise(resolve => bottomdiv.addEventListener("contentvisibilityautostatechange", resolve, { once: true }));

  let observed = false;
  bottomdiv.addEventListener("contentvisibilityautostatechange", () => {
    reject("unexpected signal")
  });

  bottomdiv.remove()
  waitForAtLeastOneFrame().then(resolve);

}), "ContentVisibilityAutoStateChange does not fire on disconnected element");

</script>

